Infrared temperature measurement and stabilization thereof

ABSTRACT

Infrared (IR) temperature measurement and stabilization systems, and methods related thereto are provided. One or more embodiments passively stabilizes temperatures of objects in proximity and within the path between an infrared (IR) sensor and target object. An overmolded sensor assembly may include an IR sensor, which may include a sensing element or IR element and a circuit or signal processor. The IR element may be thermally bonded with a frame or conductive top hat.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. Non-provisionalpatent application Ser. No. 15/312,265 entitled “INFRARED TEMPERATUREMEASUREMENT AND STABILIZATION THEREOF”, filed on Nov. 18, 2016, which isa National Stage Application of International Patent Application No.PCT/US2015/030769 entitled “INFRARED TEMPERATURE MEASUREMENT ANDSTABILIZATION THEREOF” filed on May 14, 2015 that claims priority toU.S. Non-provisional patent application Ser. No. 14/281,334 entitled“INFRARED TEMPERATURE MEASUREMENT AND STABILIZATION THEREOF”, filed onMay 19, 2014, which is a continuation-in-part (CIP) and claims priorityto U.S. Non-Provisional patent application Ser. No. 13/178,077 entitled“INFRARED TEMPERATURE MEASUREMENT AND STABILIZATION THEREOF”, filed onJul. 7, 2011 which claims the benefit of U.S. Provisional PatentApplication, Ser. No. 61/362,623 entitled “INFRARED TEMPERATUREMEASUREMENT AND STABILIZATION THEREOF”, filed on Jul. 8, 2010. Theentireties of the above-noted applications are incorporated by referenceherein.

BACKGROUND

Infrared (IR) temperature sensors can monitor infrared light which isthen converted into an electrical signal and ultimately to a temperaturereading. The spectrum of infrared radiation cannot be readily seen byhumans without the use of specially designed equipment that makes thespectrum visible. Measurement of infrared waves is calibrated inmicrons, ranging from 0.7 to 1000 microns. Today, infrared temperaturesensors can be used to measure temperature of almost any type of movingpart or object, including many used related to vehicles.

One of the most basic IR temperature sensor designs consists of a lensthat focuses IR energy onto to a detector. The detector can convert themeasured energy to an electrical signal, which can be displayed in unitsof temperature. An object's emissivity is used together with thecaptured energy in order to convert measured energy into temperature.Today, more sophisticated sensors can passively compensate for ambienttemperature variations so as to effect accurate measurement of a targetobject.

One very useful feature of IR sensors is the ability to measuretemperatures, e.g., without physical contact. This temperaturemonitoring ability is especially useful in situations where objects arein motion, e.g., in vehicular applications. Unfortunately, environmentaleffects upon the sensor require protective housings and the like to beinstalled to protect the sensors from environmental elements. Protectivehousings and the like include materials that vary in temperature andcontribute to the IR energy path of the sensor thereby making accurateand efficient temperature measurements difficult.

With regard to conventional IR temperature sensors, significantmeasurement errors often occur when the IR sensor, e.g., thermopile, issubject to thermal conditions such as a wide range in operatingtemperatures, temperature rate of change, or static thermal gradients inthe sensing region or path. Any IR visible object in the path betweenthe sensing component and the measurement target will both deliverenergy to the sensor as well as block a portion of the thermal energyemitted by object target; resulting in accurate and inefficienttemperature measurement.

BRIEF DESCRIPTION

This brief description is provided to introduce a selection of conceptsin a simplified form that are described below in the detaileddescription. This brief description is not intended to be an extensiveoverview of the claimed subject matter, identify key factors oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter.

According to one or more aspects, one or more embodiments includeinfrared (IR) temperature measurement and stabilization systems, andmethods related thereto. One or more embodiments actively stabilizestemperatures of objects in the path between an IR sensor and targetobject. A temperature monitor and controller is employed to regulatepower to resistive temperature devices (RTDs) thereby regulating current(and power) to the RTDs. As a result, temperatures of IR visible objectscan be actively stabilized for changes, for example, changes in ambienttemperatures.

With regard to traditional infrared (IR) temperature sensors,significant measurement errors often occur when the IR sensor, e.g.,thermopile, is subject to thermal conditions such as a wide range inoperating temperature, temperature rate of change, or static thermalgradients in the sensing region. IR visible objects in the path betweenthe sensing component and the measurement target will both deliverenergy to the sensor as well as block a portion of the thermal energyemitted by object target. In accordance with one or more aspects,intermediate media, such as optical lens and protective window, are heldthermally stable thereby allowing their energy contributions to be knownand precisely compensated for by the measurement system. As well, othercomponents in the sensing region can be stabilized via RTDs, e.g.,sensor housing, baseplate, etc.

Accordingly, one or more aspects can deliver a final temperatureindication response time that is significantly reduced by activelystabilizing the key measurement components. Temperature compensation,including both sensor steady-state temperature and rate of changedependencies, can be significantly reduced or eliminated by activelystabilizing the key measurement components by way of RTDs together withtemperature control components and circuitry.

In other aspects, passive stabilization of temperatures of objects in apath between a sensor and a target object is provided. In these aspectspassive thermal stabilization is accomplished via conductively couplingthe sensor to optics.

In one aspect, the innovation provides an IR temperature monitoringsystem comprising a sensor assembly encased in an overmolding material.The overmolded sensor assembly may include an IR temperature sensorhaving a sensor housing which encases an IR element. The sensor assemblymay further include a metallic frame that encompasses a transmissivewindow in the closed end of the sensor assembly, wherein the metallicframe provides a stable temperature around the transmissive window.

The following description and annexed drawings set forth certainillustrative aspects and implementations. These are indicative of but afew of the various ways in which one or more aspects may be employed.Other aspects, advantages, or novel features of the disclosure willbecome apparent from the following detailed description when consideredin conjunction with the annexed drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the disclosure are understood from the following detaileddescription when read with the accompanying drawings. Elements,structures, etc. of the drawings may not necessarily be drawn to scale.Accordingly, the dimensions of the same may be arbitrarily increased orreduced for clarity of discussion, for example.

FIG. 1 is an illustration of an example infrared (IR) temperature sensorsystem capable of component stabilization, according to one or moreembodiments.

FIG. 2 is an illustration of an example bottom view of a self-heatingtemperature sensor system, according to one or more embodiments.

FIG. 3 is an illustration of an example top-down view of a self-heatingtemperature sensor system, according to one or more embodiments.

FIG. 4 is an illustration of an example electrical schematic ofcomponents and circuitry that facilitate temperature stabilization,according to one or more embodiments.

FIG. 5 is an illustration of an example method for facilitating activetemperature stabilization, according to one or more embodiments.

FIG. 6 is an illustration of an example self-heating temperature IRsensor assembly, according to one or more embodiments.

FIG. 7 is an illustration of an example exploded view of an examplesensor assembly, according to one or more embodiments.

FIG. 8 is an illustration of an example bottom perspective view of anexample sensor assembly, according to one or more embodiments.

FIG. 9 is an illustration of an example side perspective view of anexample sensor assembly, according to one or more embodiments.

FIG. 10 is an illustration of an example bottom-up perspective view ofan example sensor assembly, according to one or more embodiments.

FIG. 11 is an illustration of yet another example perspective view of anassembly, according to one or more embodiments.

FIG. 12 is an illustration of an example placement of a conductiveframe, according to one or more embodiments.

FIG. 13 is an illustration of an example side perspective view of aprotective housing and circuit board base, according to one or moreembodiments.

FIG. 14 is an illustration of an example conductive frame, according toone or more embodiments.

FIG. 15 is an illustration of glass fillers positioned onto leads,according to one or more embodiments.

FIG. 16 is an example bottom-up perspective view of an assembly,according to one or more embodiments.

FIG. 17 is an illustration of an example infrared (IR) temperaturemonitoring system, according to one or more embodiments.

DETAILED DESCRIPTION

Embodiments or examples, illustrated in the drawings are disclosed belowusing specific language. It will nevertheless be understood that theembodiments or examples are not intended to be limiting. Any alterationsand modifications in the disclosed embodiments, and any furtherapplications of the principles disclosed in this document arecontemplated as would normally occur to one of ordinary skill in thepertinent art.

As will be described in greater detail infra, one or more embodimentsprovides for stabilization of critical measurement components as well asother ‘visible’ objects in an infrared (IR) temperature measurementsystem. One or more embodiments can effectively stabilize interferencecaused by a protective cap or housing as well as other IR ‘visible’components in close proximity to the IR sensor. As will be understood,IR thermal measurement is highly susceptible to the thermal energy stateand flux of both the sensing element and IR ‘visible’ media in (andaround) the target-object path. Active stabilization of the thermalenergy or absolute temperature of these system components is oneunderlying principal of this disclosure. This temperature stabilizationenhances accuracy and can be performed at an efficient rate as comparedto conventional IR sensor systems.

Current sensor assemblies have potential seal vulnerabilities. Suchsystems often rely on elements such as covers, glue, plugs, and potting,or a combination of such elements to provide a protective environmentfor the components within the assembly. These seal vulnerabilities maynot be ideal for all environments.

According to an aspect of the innovation, an IR temperature system maycomprise an overmolded sensor assembly in which the overmoldingencapsulates and protects components of the sensor assembly. Theovermolded sensor assembly according to the innovation eliminates theneed for a housing seal plug and adhesives or other attachments meansfor securing a separate protective cover and, thus, does not have thesame potential seal vulnerabilities.

In one aspect of the innovation, the IR temperature system does notinclude a separate protective housing. Instead, the components of thesensor assembly may be overmolded with a protective material. Suitablematerials for overmolding include most any plastic or suitably rigidmaterial. In one embodiment, the overmolding material may comprise athermoplastic material such as a polyamide thermoplastic material. Inone embodiment, the overmolding material may comprise a suitable polymerincluding acrylonitrile butadiene styrene (ABS), acetal, high-densitypolyethylene (HDPE), liquid crystal polymers (LCPs), polyethylenimine(PEI), poly(methyl methacrylate) (PMMA), polycarbonate (PC),polypropylene (PP), polyphthalamide (PPA), polyphenylene sulfide (PPS)polystyrene (PS), polysulfone (PSU), thermoplastic elastomers (TPE),thermoplastic polyurethanes (TPU), polyether ether ketone (PEEK), or anycombination of two or more thereof.

In one embodiment, the overmolding may encase all of the components ofthe sensor assembly excluding the optical components, connectors and/orcable exits. Any configuration of sensor assembly components describedherein may be encased in the overmolding material according toembodiments of the innovation.

In one embodiment, the overmolded sensor assembly may include a tophat,a sensor element, a sensor PCB, wiring (e.g., exit wires), and an insetmolded IR transparent or semi-transparent lens. In one embodiment, theovermolding material and the inset molded IR transparent orsemi-transparent lens may comprise an infrared-transmitting material. Inone embodiment, the inset molded IR transparent or semi-transparent lensmay comprise zinc sulfide, silicon, germanium, N-BK7, UV fused silicon,zinc selenide, sapphire, calcium fluoride, magnesium fluoride, sodiumchloride, potassium bromide, or the like. In one embodiment, the lensmay comprise a material selected from zinc sulfide, silicon, orgermanium. In embodiments in which the lens comprises a differentmaterial than the overmolding material, the overmolding material may beselected from any suitable overmolding material, including thosedescribed above.

Referring initially to the drawings, FIG. 1 illustrates an example IRtemperature sensor system 100 capable of active component temperaturestabilization. Generally, the system 100 can include a protectivehousing 102 (e.g., molded plastic cap) having an integral window or lens104. It will be appreciated that the lens 104 (e.g., transparent window)enables measurement of IR energy via IR temperature sensor 106 (e.g.,thermopile). It will be appreciated that this window can be manufacturedof the same material as the protective housing 102. Thus, variations intemperature of the window 104 effects accuracy of IR measurements untilits temperature is stabilized. It will be appreciated that the window104 can often represent 30 to 50% of the energy detected by thermopile106. For at least this reason, one or more embodiments is capable ofstabilizing the temperature of the window 104 such that compensation canefficiently and effectively be made to enhance accuracy of the sensingdevice 106. As shown, the temperature sensor 106 is equipped with optics108, which can also vary in temperature and effect performance of thethermopile 106.

Because the temperature of the window 104 fluctuates often duringoperation, a heat source is provided to stabilize its temperaturethereby increasing performance of the IR temperature monitoringfunctionality. Additionally, because the window 104 is most oftenmanufactured of plastic, fluctuations in temperature are slow as plasticis not an efficient conductor of heat. An example conductive metal frameequipped with resistive temperature devices (RTDs) will be described ingreater below. This conductive metal is deposited on the inner side ofthe protective housing 102 and can focus heat upon the window 104. Itwill be understood and appreciated that other aspects can include anoptional temperature directional means (e.g., cone-like device) thatcaptures heat from a conductive source equipped with RTDs and channelsthat heat to the window 104 and components of the sensor 106. In otherwords, in one or more aspects and environments, the heating effects andefficiency as described herein can be affected by the low conductivityof the captive air within the protective housing. By providing atemperature channeling means, e.g., funnel, (illustrated as dashed lines110), heat can be contained within the inner area of the cone, therebyenhancing stabilization effects.

It will be appreciated that measurement system errors of several degreesexists under current or traditional measurement techniques. Laborious,time consuming and expensive calibration processes are required tocompensate over varying temperature ranges. Other techniques have beenattempted to passively control temperature of intermediate media usinginsulating and conducting materials. Unfortunately, these techniques arecomplicated and result in delayed temperature readings. Further, passivecontrol of intermediate media temperatures oftentimes results in erroror inaccurate readings. It will be appreciated many applications requirehigh accuracy in IR temperature measurements. The active temperaturestabilization systems of one or more embodiments can provide thisaccuracy.

Traditionally, intrinsic errors in IR temperature measurements weretolerated. Additionally, the optical lens or raw sensor was protectedfrom environmental elements by looking through narrow chambers or longtubes. Still further, in accordance with traditional systems,environmentally protective barriers were removed as they led tocomplexity that resulted in inaccurate readings. Devices took a longtime in temperature stable environments to indicate accurately.

In accordance with traditional systems, temperature compensation iscurrently handled by collecting sensor responses over a wide range oftemperatures. Thereafter, the indication is adjusted using sensor uniquecorrection factors. This is both time consuming and leads to compromisedaccuracy. Large thermal masses are added to slow temperature rates ofchange and to resolve thermal gradients. Unfortunately, this approachleads to enhanced device size and longer thermal response times.

The measurement system 100 of FIG. 1 can actively control the thermalenvironment of key components of the IR measurement system. Following isa review of options available to stabilize temperatures. One techniqueof the sensor systems allows the sensor 106 to come into thermalequilibrium shortly after the environment temperature and heat sourcesstabilize. To accomplish this, the thermopile sensor 106 is exposeddirectly to the environment with little or no protection from corrosiveor harsh environments. This direct exposure is needed in order for itstemperature to track the environmental temperature in a reasonableamount of time. Unfortunately, direct exposure results in damage andcorrosive elements upon the sensor.

Another alternative technique employs thermal separation of heatsources, such as power dissipating electronic components, whileenhancing passive thermal conduction between a protective cover andenvironmental media heat transfer. It will be understood thattraditional products have limited performance over wide ambienttemperature range.

Overall, the IR system 100 of FIG. 1 can offer improved accuracy in viewof conventional systems by way of active temperature stabilization.Additionally, more accurate temperatures can be rendered in a fasterresponse time. The system 100 employs simplification that results inreduced time related to the calibration process. Overall end cost can bereduced in view of the efficiencies offered by the features, functions,and benefits of the disclosure. Still further, the sensor 106 and system100 can have a wider application base. Thus, one or more embodiments mayprovide a versatile system adaptable to a wide range of uses orapplications.

Turning now to FIG. 2, a bottom view of an example self-heatingtemperature sensor 200 is shown. Item 202 is illustrative of a baseplateof the thermopile of FIG. 1. An RTD 204 capable of detecting andgenerating heat can be thermally bonded to the baseplate 202.Accordingly, in addition to detecting thermal power, RTD 204 can alsogenerate heat thereby stabilizing the temperature of the baseplate 202,along with other components of the system. Lead apertures 206 are shownand provide means by which thermopile leads can traverse the baseplate202 to accompanying circuitry.

FIG. 3 illustrates a top view of an example stabilization system 300 inaccordance with one or more aspects. Generally, system 300 includes aprotective cover 302 having a lens 304 (or window) provided on the topsurface of the protective cover (302). In aspects, the window 304 isintegral to the cover however, can also be a separate component inalternative designs. As described supra, the protective cover 302encases components of an IR sensor system (e.g., system 100 of FIG. 1).

The temperature and temperature movement of the lens 304 (or window) iseffectively noise to the IR detection of the system resulting ininaccurate readings. In accordance thereto, one or more embodimentsprovides for temperature stabilization of the lens 304. Essentially, thelens 304 is an IR transmissive window 304 bordered by a metalized copper(Cu) frame 306. The frame 306 is deposited upon the inner surface of theprotective cover 302 and can focus heat around the window 304. While asquare frame is shown, it will be understood that other shapes anddeposits of conductive material (e.g., copper) that focus heat upon thewindow 304 can be employed without departing from the spirit and/orscope of the disclosure. Additionally, other conductive metals, e.g.,platinum, silver, etc. can be employed in alternative aspects.Self-heating resistive temperature sensors 308 (e.g., RTDs) can beprovided so as to control the self-heating functionality of one or moreembodiments. It will be understood that the RTDs 308 can detect anddeliver thermal power as appropriate for temperature stabilization.While two RTDs are shown, other aspects can employ additional or fewerRTDs as appropriate without departing from the scope of the disclosureor claims appended hereto.

FIG. 4 depicts an example electrical schematic 400 in accordance withone or more aspects. As shown, a self-heating temperature sensor 402(e.g., RTD) can be electrically coupled to temperature measurement andtemperature control components included within a thermal controlcircuitry 404. In accordance with a desired temperature setpoint, RTDs402 can measure and control temperature by varying power dissipation. Inother words, RTD 402 resistance will represent a certain temperature andthe power provided to the RTD 402 will be proportional to the squareroot of the current passing through the RTD 402. In operation, aparticular setpoint temperature can be selected (e.g., 120° F.), wherebythe RTD can be provided with a requisite amount of power so as toachieve the desired temperature. Within the thermal control circuitry404, the temperature can be measured as shown. In accordance with thismeasured temperature, the temperature control can provide enough powerto the self-heating temperature sensor (RTD) 402 to achieve thetemperature setpoint as desired.

Thus, the temperature control can vary the power based on a presentand/or desired temperature. Therefore, heat loss can be automatically oractively compensated for and stabilized in an active control of thethermal environment of the location(s) of the RTD(s). It will beunderstood that this process of regulating temperature can also beutilized with regard to all RTDs provided within systems, such as RTDsbonded to conductive metal within the protective housing as describedbelow.

FIG. 5 illustrates a methodology 500 of stabilizing components in an IRtemperature measurement system in accordance with one or more aspects.While, for purposes of simplicity of explanation, the one or moremethodologies shown herein, e.g., in the form of a flow chart, are shownand described as a series of acts, it will be understood and appreciatedthat one or more acts may, in accordance with one or more aspects, occurin a different order and/or concurrently with other acts from that shownand described herein. For example, those skilled in the art willunderstand and appreciate that a methodology could alternatively berepresented as a series of interrelated states or events, such as in astate diagram. Moreover, not all illustrated acts may be required toimplement a methodology in accordance with one or more aspects.

At 502, a temperature setpoint can be established. For example, asetpoint of 120° F. can be selected in aspects so as to exceed most anyambient operating conditions. As described above, an IR sensor assemblycan be equipped with a number of RTDs so as to actively stabilizecomponent temperatures. For example, a conductive frame can be equippedwith RTDs so as to focus heat upon a transmissive window in a protectivehousing. Similarly, an RTD can be bonded to a baseplate of a thermopileand can provide temperature stabilization.

At 504, temperature can be monitored via the RTD. As will be understood,the RTDs employed in connection with one or more aspects can bothmonitor and deliver heat as desired. A decision is made at 506 todetermine if the monitored temperature is consistent with the desiredtemperature setpoint. If yes, the methodology returns to 504 to monitorthe temperature.

If not consistent at 506, power to the RTD can be regulated at 508.Thus, the temperature output of the RTD can be regulated (e.g., raised)at 510. As will be appreciated, the rise in temperature can effectivelyregulate and/or stabilize IR ‘visible’ components within the protectivehousing and within the IR measurement object-target path.

Referring now to FIG. 6, illustrated is an example self-heatingtemperature sensor assembly 600 in accordance with one or more aspects.As shown in the example of FIG. 6, a protective housing 602 encasesthermopile or sensor 604. For example, the protective housing 602shelters, shields and/or safeguards the sensor 604 from environmentaleffects. A circuit board 606 is provided upon which sensor 604 can bemounted. It will be understood and appreciated that circuitry can bedisposed upon the board so as to control the sensor 604 for temperaturemeasurement and thermal stabilization control via RTDs as describedherein. As illustrated, the circuit board 606 is of a shape consistentwith the protective housing 602. A metalized frame 608 can be providedand equipped with RTDs that facilitate self-heating functionality.

In one embodiment, the IR temperature sensor system may include a sensorassembly encased by an overmolding material. In this embodiment, theprotective housing may be unnecessary as the overmolding materialprotects the components of the sensor assembly (e.g., the IR temperaturesensor).

FIG. 7 illustrates an exploded (and assembled) view of a sensor assembly700 in accordance with one or more aspects. As illustrated, the assembly700 can include a protective housing 702 that encases sensor components.In aspects, the protective housing can be manufactured of most anyplastic or suitably rigid material.

The protective housing 702 shields a sensor housing 704, for example,from environmental effects. The sensor housing 704 can be manufacturedof stainless steel or most any other suitably rigid material. Asillustrated in FIG. 1 discussed supra, a sensor optic lens 706 can befitted atop the sensor housing 704. The lens 706 is transparent and canbe manufactured of silicon or other suitably transparent or translucentmaterial.

A baseplate 708 is disposed upon an end of the sensor housing 706opposite the lens 706. In aspects, the baseplate 708 is manufactured ofstainless steel. However, it will be understood and appreciated thatmost any suitable material can be employed without departing from thespirit and/or scope of the disclosure or claims appended hereto. Aresistive temperature detector (RTD) 710 can be mounted or thermallybonded beneath the baseplate 708, thereby temperature stabilization ofcomponents (e.g., 708, 706, and 704) can be effected via RTD 710. Inaspects, RTD 710 can be a ceramic RTD.

The RTDs may be capable of use in a mode that can measure temperatureand deliver heat simultaneously. Thus, this single component (e.g., RTD)is capable of functionally measuring temperature while at the same timeworking to stabilize temperatures of other IR ‘visible’ components(e.g., housing, baseplate, optic lens, protective housing window, etc.).The RTDs can be controlled by a circuit that facilitates maintenance ofa particular temperature or setpoint (e.g., 120° F.).

Accordingly, the circuitry can regulate power to the RTD to maintain thedesired temperature. While specific temperatures and power sources aredescribed herein, the features, functions, and benefits may be employedto maintain most any desired temperature by providing power or wattageas appropriate. It will be appreciated that stabilization of thecritical component's temperature enhances accuracy and performance ofthe IR temperature sensing functionality.

As illustrated, glass fillers 712 can be fitted into holes of thebaseplate 708. The glass fillers 712 can enhance the hermetic seal inaddition to the seal of the protective housing 702 mounted onto thecircuit board 718. Upon manufacture, leads, e.g., copper leads, 714 canbe inserted through the glass fillers 712 and into the baseplate 708. Atrace, e.g., copper trace, 716 can be provided in embodiments. A circuitboard 718 can be fitted onto the open end of the protective housing 702,thereby encasing sensor components therein. It will be appreciated thatthe circuit board 718 can be of a shape consistent with an open end ofthe protective housing 702. In other aspects, a groove that isconsistent with the shape of the open end of protective housing 702 canbe provided so as to provide a suitable hermetic seal.

Also included within the protective housing 702 is a metalized frame,e.g., copper frame, 720. The copper frame 720 can be equipped with RTDs722. In one aspect, RTDs 722 are ceramic detectors. While RTD 710 candetect temperature and provide heat to the baseplate 708 region, theRTDs 722 can provide heat to the protective housing window region asshown. It will be appreciated that the RTDs 722 can provide heat to themetalized frame which can conduct heat around the window. By focusingheat upon the window, temperature can be evenly stabilized to enhance IRmeasurement functionality.

FIG. 8 is a bottom perspective view of an example sensor assembly 800 inaccordance with one or more aspects. As shown, the sensor assembly 800can include a protective housing 802, a circuit board 804 and an RTD806. Additionally copper leads 808 are provided so as to facilitateelectrical connection as appropriate.

Referring now to FIG. 9, a side perspective view of an example sensorassembly 900 is shown. As illustrated, protective housing 902 can beequipped with a translucent window 904 on the top such that IR energycan be captured via a sensor or thermopile. The bottom section of theprotective housing 902 is open such that sensor components can beinserted as described with regard to FIG. 7 supra. Further, the open endof the protective housing 902 can be configured to mate to a circuitboard 906, e.g., providing a waterproof or hermetic seal. It will beunderstood that, where appropriate, gaskets can be provided to assistwith or enhance the sealing functionality.

FIG. 10 illustrates a bottom-up perspective view of an example sensorassembly 1000 in accordance with aspects. From this vantage point,placement of glass fillers 1002 can be can be seen. In other words, eachof the leads 1004 is passed through a glass filler 1004 upon insertioninto the circuit board 1006.

FIG. 11 is yet another perspective view of an assembly 1100 inaccordance with aspects. As shown, a sensor component 1102 can bedisposed within the center of circuit board 1104. In other aspects, thesensor component 1102 can be mounted upon an end cap that does notinclude circuitry. In these alternative aspects, the circuitry can beremotely located from the thermopile. It will be appreciated that thisillustration is exemplary and not intended to limit alternative aspectsdisclosed herein.

FIG. 12 illustrates an example 1200 placement of a frame 1202 within theclosed face of protective housing 1204. In other words, the metal, e.g.,copper, frame 1202 is encased within the protective housing 1204together with other sensor components as described in greater detailsupra. Further, the metal frame 1202 can be equipped with RTDs 1206 asshown. These RTDs 1206 can provide information necessary for temperaturestabilization in accordance with the features, functions, and benefitsof the disclosure. As well, the RTDs 1206 can provide heat as necessaryfor stabilization effect.

FIG. 13 to FIG. 16 are shown in accordance with one or more aspects.While specific heat capacities and conductivities are disclosed, it willbe understood that these values and parameters are provided forperspective and are not limiting in any manner.

Referring first to the assembly 1300 of FIG. 13, protective housing1302, e.g., plastic, can have a specific heat capacity of 2200 J/Kg ° Kand a conductivity of 0.5 W/m ° K. Circuit board 1304 can have aspecific heat capacity of 1200 J/Kg ° K and a conductivity of 0.23 W/m °K.

The frame 1400 of FIG. 14 can have a specific heat capacity of 385 J/Kg° K and a conductivity of 398 W/m ° K. The glass fillers 1502 of FIG. 15can have a conductivity of 0.836 W/m ° K, as seen at 1500.

As shown in the assembly 1600 of FIG. 16, a sensor housing 1602, e.g.,steel housing, can have a specific heat capacity of 477 J/Kg ° K. Thesensor housing 1602 can also have a conductivity of 16.7 W/m ° K inaspects. Consistent with the sensor housing 1602, the baseplate 1604,e.g., steel, can have a specific heat capacity of 477 J/Kg ° K and aconductivity of 16.7 W/m ° K. The leads 1606, e.g., copper leads, canhave a specific heat capacity of 385 J/Kg ° K and a conductivity of 398W/m ° K.

In accordance with one or more aspects, it will be understood that heattransfer is a through conduction in a component and wherever twocomponents come into contact. The outer surface of the protectivehousing can convect with the ambient temperature. The inner surface ofthe protective housing and the outer surface of the other componentswithin the protective housing (e.g., sensor housing) will convect withthe captive air that is trapped inside the protective housing. Inembodiments, convective heat transfer coefficient of 7.9 W/M̂2 K is used.

In accordance with the aforementioned heat capacities andconductivities, a power source of 0.196 W was specified at each RTD. Theambient temperature was fixed as −20° C. Upon testing, a power source of0.196 W was applied at each RTD. The RTDs at the copper frame to reacheda temperature of about 120° F. The temperature at RTD near the baseplatefor this power is 101° F. It will be understood that this amount ofstabilization is sufficient to enable efficient and accurate IRtemperature measurements. In other words, control circuitry can beprovided so as to use the stabilized component temperatures in IR energyto temperature conversions. As a result, effects of IR ‘visible’components are alleviated.

While active stabilization has been disclosed and described in detailherein, it will be understood that passive (or combinations of activeand passive) stabilization embodiments are to be contemplated andincluded within the scope of the disclosure and claims appended hereto.For instance, in a passive embodiment, the sensor component(s) may bethermally coupled to the optics so as to effect passive stabilization.In other words, the cover (e.g., including optics) can be metalizedusing a conductive material (e.g., copper). Here, the passiveconductivity of thermal properties via the conductive metal can be usedto stabilize the temperature(s) as described herein.

FIG. 17 is an illustration of an exploded view of an example infrared(IR) temperature monitoring system 1700, according to one or moreembodiments. The system 1700 may provide for passive temperaturestabilization by thermally bonding a protective housing 1702 orprotective shell, such as a protective plastic housing, to a sensingelement 1712. In one or more embodiments, the protective housing 1702has an open end and a closed end. The protective housing 1702 may beformed of a non-thermally conductive, corrosion resistant material.Additionally, the protective housing 1702 may have an integral thinwindow 1710 of IR transmissive plastic. As seen in FIG. 17, the open endof the protective housing 1702 may couple with a frame, which may beformed of metal. For example, the frame 1704 may be a metallic frame ora conductive frame having an open top hat shape. It will be appreciatedthat the frame 1704 may be inset formed, bonded, or pressed to fitfirmly against the closed end face of the protective housing 1702. Theframe 1704 may be positioned upon an inner face or portion of the closedend of the protective housing 1702. In other words, the frame 1704 maybe pressed into tight contact with the protective housing 1702effectively stabilizing the otherwise non-conductive plastic window. Thecylinder end may fit snuggly around the IR element 1712 or sensorelement. In one or more embodiments, the snug fit may further beenhanced by the use of thermal grease or thermally conductive adhesive.The top hat in situ then thermally stabilizes and maintains a uniformtemperature between the outside media and the sensing element 1712.Further stated, the frame 1704 may encompass a transmissive window inthe closed end of the protective housing 1702 to facilitate providing astable temperature around the transmissive window. Additionally, theassembly or system 1700 may include an infrared (IR) element, such as athermopile IR detector 1712, a circuit or signal processor 1714, and ahousing plug 1716 or housing seal plug.

In one or more embodiments, a sensor assembly may include the IR element1712, the signal processor 1714, and the housing seal plug 1716, whichseals the system 1700. Accordingly, the system 1700 may include theprotective housing 1702, the frame 1704, and the sensor assembly. Itwill be appreciated that one or more of the components described hereinmay be bonded and/or sealed for harsh environment use. In other words,components 1702 and 1704 may be thermally coupled with 1712, 1714, and1716 such that a temperature of a protective housing lens (e.g., withinthe protective housing 1702) does not disrupt an intended temperature,setpoint temperature, or target temperature measurement. In this way,the system 1700 links a temperature of an outside environment or enablesan outside, external, or ambient temperature measurement to be made.Further, lens temperature compensation may be provided as well.

According to one or more aspects, infrared (IR) temperature monitoringsystem is provided, including a protective housing, an IR temperaturesensor, and a metallic frame. The protective housing may have an openend and closed end. The IR temperature sensor may have a sensor housingwhich encases an IR element. The protective housing may encase the IRtemperature sensor and the sensor housing. The protective housing may bea cap that shields the sensor housing from one or more environmentaleffects. The metallic frame may be positioned upon an inner portion ofthe closed end of the protective housing, wherein the metallic frameencompasses a transmissive window in the closed end of the protectivehousing, wherein the metallic frame provides a stable temperature aroundthe transmissive window.

In one or more embodiments, the protective housing encases the IRtemperature sensor. The IR element may be positioned on a signalprocessor. The metallic frame may be a conductive top hat. The systemmay include a housing seal plug. The protective housing may becylindrical in shape or formed of plastic. The metallic frame may beformed of copper, aluminum, or other suitable thermalconductor/thermally conductive material. The sensor housing may beformed of plastic that acts as a lens arranged at one end of the IRelement and a baseplate mounted to the other end of the IR element. Thesystem may include one or more glass fillers that hermetically seal oneor more leads traversing through a baseplate of the IR element.

According to one or more aspects, a method for infrared (IR) temperaturemonitoring is provided, including encasing an IR element of an IRtemperature sensor with a sensor housing, encasing the IR temperaturesensor and the sensor housing with a protective housing having an openend and closed end, wherein the protective housing is a cap that shieldsthe sensor housing from one or more environmental effects, andpositioning a metallic frame upon an inner portion of the closed end ofthe protective housing, wherein the metallic frame encompasses atransmissive window in the closed end of the protective housing, whereinthe metallic frame provides a stable temperature around the transmissivewindow. The protective housing may include an integral lens formed ofthe same material as the protective housing. The IR element may bepositioned on a signal processor. The signal processor may beimplemented as a circuit. The housing plug or housing seal plug may fitwith the assembly 1700 of FIG. 17 to complete an internal system sealimpervious to one or more environmental effects.

According to one or more aspects, an infrared (IR) temperaturemonitoring system is provided, including a protective housing having anopen end and closed end, an IR temperature sensor having a sensorhousing which encases an IR element, wherein the protective housingencases the IR temperature sensor and the sensor housing, wherein theprotective housing is a plastic cap that shields the sensor housing andthe IR temperature element from one or more environmental effects, ametallic frame positioned upon an inner portion of the closed end of theprotective housing, wherein the metallic frame encompasses atransmissive window in the closed end of the protective housing, whereinthe metallic frame provides a stable temperature around the transmissivewindow, and a housing seal plug which completes an internal system sealimpervious to external environment effects.

Although the subject matter has been described in language specific tostructural features or methodological acts, it will be understood thatthe subject matter of the appended claims is not necessarily limited tothe specific features or acts described above. Rather, the specificfeatures and acts described above are disclosed as example embodiments.

Various operations of embodiments are provided herein. The order inwhich one or more or all of the operations are described should not beconstrued as to imply that these operations are necessarily orderdependent. Alternative ordering will be appreciated based on thisdescription. Further, not all operations may necessarily be present ineach embodiment provided herein.

As used in this application, “or” is intended to mean an inclusive “or”rather than an exclusive “or”. Further, an inclusive “or” may includeany combination thereof (e.g., A, B, or any combination thereof). Inaddition, “a” and “an” as used in this application are generallyconstrued to mean “one or more” unless specified otherwise or clear fromcontext to be directed to a singular form. Additionally, at least one ofA and B and/or the like generally means A or B or both A and B. Further,to the extent that “includes”, “having”, “has”, “with”, or variantsthereof are used in either the detailed description or the claims, suchterms are intended to be inclusive in a manner similar to the term“comprising”.

Further, unless specified otherwise, “first”, “second”, or the like arenot intended to imply a temporal aspect, a spatial aspect, an ordering,etc. Rather, such terms are merely used as identifiers, names, etc. forfeatures, elements, items, etc. For example, a first channel and asecond channel generally correspond to channel A and channel B or twodifferent or two identical channels or the same channel. Additionally,“comprising”, “comprises”, “including”, “includes”, or the likegenerally means comprising or including, but not limited to.

Although the disclosure has been shown and described with respect to oneor more implementations, equivalent alterations and modifications willoccur based on a reading and understanding of this specification and theannexed drawings. The disclosure includes all such modifications andalterations and is limited only by the scope of the following claims.

What is claimed is:
 1. An infrared (IR) temperature monitoring system,comprising: a sensor assembly encased by an overmolding material, theovermolded sensor assembly having an open end and closed end, the sensorassembly comprising: an IR temperature sensor having a sensor housingwhich encases an IR element, wherein the overmolding material encasesthe IR temperature sensor and the sensor housing; and a metallic frame,wherein the metallic frame encompasses a transmissive window in theclosed end of the sensor assembly, wherein the metallic frame provides astable temperature around the transmissive window.
 2. The system ofclaim 1, wherein the IR element is positioned on a signal processor. 3.The system of claim 1, wherein the metallic frame is a conductive tophat.
 4. The system of claim 1, wherein the overmolding material isplastic.
 5. The system of claim 1, wherein the metallic frame is formedof copper, aluminum, or other thermally conductive material.
 6. Thesystem of claim 1, wherein the sensor housing is formed of plastic thatacts as a lens arranged at one end of the IR element and a baseplatemounted to the other end of the IR element.
 7. The system of claim 1,comprising one or more glass fillers that hermetically seal one or moreleads traversing through a baseplate of the IR element.
 8. A method forinfrared (IR) temperature monitoring, comprising: encasing an IR elementof an IR temperature sensor with a sensor housing; encasing the IRtemperature sensor and the sensor housing with an overmolding materialto form an overmolded sensor assembly, the overmolded sensor assemblyhaving an open end and closed end; and positioning a metallic frame uponan inner portion of the closed end of the sensor assembly, wherein themetallic frame encompasses a transmissive window in the closed end ofthe sensor assembly, wherein the metallic frame provides a stabletemperature around the transmissive window.
 9. The method of claim 8,wherein the overmolded sensor assembly comprises an integral lens formedof the same material as the overmolding material.
 10. The method ofclaim 8, wherein the IR element is positioned on a signal processor. 11.The method of claim 10, wherein the signal processor is implemented as acircuit.
 12. The method of claim 8, wherein the metallic frame is aconductive top hat.
 13. The method of claim 8, wherein the overmoldedsensor assembly is cylindrical in shape.
 14. The method of claim 8,wherein the overmolding material is plastic.
 15. The method of claim 8,wherein the metallic frame is formed of copper, aluminum, or otherthermally conductive material.
 16. A method for infrared (IR)temperature monitoring, comprising: encasing an IR element of an IRtemperature sensor with a sensor housing; encasing the IR temperaturesensor and the sensor housing with an overmolding material to form anovermolded sensor assembly, the overmolded sensor assembly having anopen end and closed end; and positioning a metallic frame upon an innerportion of the closed end of the sensor assembly, wherein the metallicframe encompasses a transmissive window in the closed end of the sensorassembly, wherein the metallic frame provides a stable temperaturearound the transmissive window; an inset molded IR transparent orsemi-transparent lens such that a seamless overmolded seal is achievedbetween the lens and the sensor assembly and the lens is in closethermal contact to metallic frame and sensor element.